/***************************************************************************/
/*                                                                         */
/*  gxvopbd.c                                                              */
/*                                                                         */
/*    TrueTypeGX/AAT opbd table validation (body).                         */
/*                                                                         */
/*  Copyright 2004, 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K., */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/

/***************************************************************************/
/*                                                                         */
/* gxvalid is derived from both gxlayout module and otvalid module.        */
/* Development of gxlayout is supported by the Information-technology      */
/* Promotion Agency(IPA), Japan.                                           */
/*                                                                         */
/***************************************************************************/


#include "gxvalid.h"
#include "gxvcommn.h"


/*************************************************************************/
/*                                                                       */
/* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
/* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
/* messages during execution.                                            */
/*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT trace_gxvopbd


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                      Data and Types                           *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/

typedef struct  GXV_opbd_DataRec_
{
    FT_UShort format;
    FT_UShort valueOffset_min;

} GXV_opbd_DataRec, * GXV_opbd_Data;


#define GXV_OPBD_DATA(FIELD)  GXV_TABLE_DATA(opbd, FIELD)


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                      UTILITY FUNCTIONS                        *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/

static void
gxv_opbd_LookupValue_validate(FT_UShort glyph,
                              GXV_LookupValueCPtr value_p,
                              GXV_Validator valid)
{
    /* offset in LookupTable is measured from the head of opbd table */
    FT_Bytes p = valid->root->base + value_p->u;
    FT_Bytes limit = valid->root->limit;
    FT_Short delta_value;
    int i;


    if (value_p->u < GXV_OPBD_DATA(valueOffset_min))
        GXV_OPBD_DATA(valueOffset_min) = value_p->u;

    for (i = 0; i < 4; i++)
    {
        GXV_LIMIT_CHECK(2);
        delta_value = FT_NEXT_SHORT(p);

        if (GXV_OPBD_DATA(format))      /* format 1, value is ctrl pt. */
        {
            if (delta_value == -1)
                continue;

            gxv_ctlPoint_validate(glyph, delta_value, valid);
        }
        else                            /* format 0, value is distance */
            continue;
    }
}


/*
   opbd ---------------------+
 |
 +===============+         |
 | lookup header |         |
 +===============+         |
 | BinSrchHeader |         |
 +===============+         |
 | lastGlyph[0]  |         |
 +---------------+         |
 | firstGlyph[0] |         |  head of opbd sfnt table
 +---------------+         |             +
 | offset[0]     |    ->   |          offset            [byte]
 +===============+         |             +
 | lastGlyph[1]  |         | (glyphID - firstGlyph) * 4 * sizeof(FT_Short) [byte]
 +---------------+         |
 | firstGlyph[1] |         |
 +---------------+         |
 | offset[1]     |         |
 +===============+         |
 |
   ....                     |
 |
   48bit value array         |
 +===============+         |
 |     value     | <-------+
 |               |
 |               |
 |               |
 +---------------+
   .... */

static GXV_LookupValueDesc
gxv_opbd_LookupFmt4_transit(FT_UShort relative_gindex,
                            GXV_LookupValueCPtr base_value_p,
                            FT_Bytes lookuptbl_limit,
                            GXV_Validator valid)
{
    GXV_LookupValueDesc value;

    FT_UNUSED(lookuptbl_limit);
    FT_UNUSED(valid);

    /* XXX: check range? */
    value.u = (FT_UShort)(base_value_p->u +
                          relative_gindex * 4 * sizeof(FT_Short));

    return value;
}


/*************************************************************************/
/*************************************************************************/
/*****                                                               *****/
/*****                         opbd TABLE                            *****/
/*****                                                               *****/
/*************************************************************************/
/*************************************************************************/

FT_LOCAL_DEF(void)
gxv_opbd_validate(FT_Bytes table,
                  FT_Face face,
                  FT_Validator ftvalid)
{
    GXV_ValidatorRec validrec;
    GXV_Validator valid = &validrec;
    GXV_opbd_DataRec opbdrec;
    GXV_opbd_Data opbd = &opbdrec;
    FT_Bytes p = table;
    FT_Bytes limit = 0;

    FT_ULong version;


    valid->root = ftvalid;
    valid->table_data = opbd;
    valid->face = face;

    FT_TRACE3(("validating `opbd' table\n"));
    GXV_INIT;
    GXV_OPBD_DATA(valueOffset_min) = 0xFFFFU;


    GXV_LIMIT_CHECK(4 + 2);
    version = FT_NEXT_ULONG(p);
    GXV_OPBD_DATA(format) = FT_NEXT_USHORT(p);


    /* only 0x00010000 is defined (1996) */
    GXV_TRACE(("(version=0x%08x)\n", version));
    if (0x00010000UL != version)
        FT_INVALID_FORMAT;

    /* only values 0 and 1 are defined (1996) */
    GXV_TRACE(("(format=0x%04x)\n", GXV_OPBD_DATA(format)));
    if (0x0001 < GXV_OPBD_DATA(format))
        FT_INVALID_FORMAT;

    valid->lookupval_sign = GXV_LOOKUPVALUE_UNSIGNED;
    valid->lookupval_func = gxv_opbd_LookupValue_validate;
    valid->lookupfmt4_trans = gxv_opbd_LookupFmt4_transit;

    gxv_LookupTable_validate(p, limit, valid);
    p += valid->subtable_length;

    if (p > table + GXV_OPBD_DATA(valueOffset_min))
    {
        GXV_TRACE((
                      "found overlap between LookupTable and opbd_value array\n"));
        FT_INVALID_OFFSET;
    }

    FT_TRACE4(("\n"));
}


/* END */